An alpha-beta titanium-base alloy exhibits an alpha-plus-beta phase field in its temperature-composition equilibrium phase diagram. These alpha-beta titanium-base alloys may be heat treated for improved performance. Alpha-beta titanium-base alloys are used in applications requiring good mechanical performance at intermediate temperatures, coupled with their relatively low density. For example, such alpha-beta titanium-base alloys are used in compressor blades, disks, and structures of aircraft engines, where the article is expected to perform at temperatures of up to about 1100.degree. F.
Alpha-beta titanium-base alloys are potentially susceptibility to dwell fatigue damage. In dwell fatigue, the material is loaded and held with the load applied for a period of time, and then unloaded. The loading and unloading cycle is repeated numerous times. Such loading conditions are experienced in typical situations of use of the alpha-beta titanium-base alloys. Under these conditions, the alpha-beta titanium-base alloy may crack and fail prematurely.
There is a need for an approach that reduces the incidence of dwell fatigue in alpha-beta titanium-base alloys, while retaining the other beneficial properties of the material. The present invention fulfills this need, and further provides related advantages.